Corrosion resistance of nickel-based alloy to gaseous hydrogen iodide decomposition environment in thermochemical water-splitting iodine-sulfur process

Kamiji, Yu; Onuki, Kaoru; Kubo, Shinji  

As one of the evaluation of corrosion resistance of structural materials for HI decomposition environment in the iodine-sulfur (IS) thermochemical water-splitting process, we fabricated a HI decomposer which produce practical corrosion environment for the corrosion test using test specimens and examined corrosion resistance of test specimens made of Hastelloy C-276. In the corrosion test, dry HI as the feed gas were used to realize practical environment with copresence of no steam. The experiments were carried out at 500C and atmospheric pressure for 100h in total. Corrosion rates were evaluated from the weight change of each specimen after exposure. Test specimens set in the catalyst layer suffered relatively severe corrosion ( 0.75 mm/y) in comparison with those set before the catalyst layer ( 0.52 mm/y).